TELEVISION: MYSTERY SHOT

THE AIM OF ALTMAN'S GUN IS ANYONE'S GUESS

To a certain kind of discerning television viewer it remains a pop-culture mystery why millions more Americans this season tuned to CBS's lead-armed Walker, Texas Ranger on Saturday nights than to ABC's nuanced romantic drama Relativity. To many TV producers this is not a vexing question, however. Nothing is more dramatic than the conflict between life and death, they will tell you (even if the conflict involves Chuck Norris). Slice-of-life series almost never win the ratings that crime shows pull in, which is why eight of the nine new network dramas premiering this spring feature people yelling out lines like "Get...